Different jurisdictions have different requirements for equipping and operating load-bearing transport vehicles. for example, the province of Ontario, Canada has a series of explicit requirements for “safe, productive and infrastructure-friendly vehicles” found in Regulation 413/05 under the Highway Traffic Act. The requirements include the use of an automatic device that locks the rearmost self-steering axle in the straight ahead position when a tractor-trailer is travelling at a speed over 60 kilometers per hour.
Electronic and mechanical technology related to large vehicles has been outlined in previous patent publications. By way of illustration, the following patents and publications relate to a broad spectrum of vehicle construction, monitoring, and operation.
U.S. Pat. No. 7,568,710 refers to a sensor system for actuating the lifting of a steerable axle of a vehicle. U.S. Pat. Nos. 4,854,409; 6,572,124; 6,810,982; 7,735,516 generally refer to lift axle control systems. U.S. Pat. No. 7,222,867 refers to a positioning system for a lift axle for wheeled vehicles, in which an electrical system controller is programmed to issue instructions to the lift axle means responsive to the values of the load sensors, the vehicle speed sensor, the transmission controller, the park brake position sensor and the ignition switch position sensor.
U.S. Pat. No. 5,959,365 (J. Mantini et al.) describes an early warning device for tire rims and hub assemblies. It provides a monitoring system for detecting problems associated with the wheels on vehicle axles, with one or more sensors located on the vehicle axles adjacent the wheels, a programmable micro processor for receiving and processing the sensor signals to detect an alarm condition and an alarm to alert the driver of a problem with one or more of the wheels wherein said sensors detect heat, noise or vibration. U.S. patent publication 2002/0019688 A1 describes an apparatus to monitor the rotation of the brake cam shaft, having a sensor that can convert the rotational movement of the brake cam shaft to an electrical signal.
U.S. Pat. No. 6,921,100 and describes a system for adjusting weight distribution throughout axle groups of a truck and trailer. The technology involves measuring the weight on every axle group on the truck and trailer, detecting the position of said at least one axle group on the trailer relative to said rails, calculating the weight on each axle group and determine a needed change in position on the rails to optimize the weight distribution.
U.S. Pat. No. 7,408,452 refers to a wireless wheel speed sensor. U.S. Patent publication 2009/0109066 A1 refers to a wireless wheel-sensor system for dead reckoning navigation applications. U.S. Pat. No. 6,830,250 outlines a system for automatically and simultaneously controlling one or more vehicle functions by detecting the direction of movement of and the distance traveled by the vehicle. The proposed control system includes an electronic sensor mounted on a selected one of the vehicle axles adjacent to and facing an anti-lock braking system tone ring. The sensor is electrically connected to an electronic control module, which in turn is electrically connected to a vehicle function actuation device such as a lift axle solenoid or back-up alarm actuation device.
U.S. Pat. Nos. 4,336,720 and 5,681,998 refer to a load sensing system or device for a vehicle. U.S. Pat. No. 6,259,041 refers to an onboard indicator for measuring the weight of vehicles. U.S. Pat. No. 7,216,024 generally describes an industrial truck with a stabilizing device. U.S. Pat. No. 7,677,339 is entitled Vehicle Suspension Arrangement. Published U.S. application 2008/0250894 A1 refers to a load-sensor-equipped device. Published U.S. application 2008/0285901 A1 provides a wheel support bearing assembly.
High technology vehicle operating equipment is available commercially from Wheel Monitor Inc., Niagara-on-the-Lake, Ontario. The Reverse-A-Matic™ is a trailer direction sensing system that automatically locks or lifts a self-steer axle. The RM-60 model will also lift the forward axle when the four way flashers are activated. The device transfers weight onto the drive axles for increased traction during slippery uphill conditions. The Balancer™ is an electronic liftable axle control for lifting axles when not in use. It monitors the axle load weight and lifts automatically when the trailer is empty. The Proviso™ is an electronic lift axle control system that lifts and locks axles when a vehicle is in reverse, and also has an automatic lift function based on axle load weight. It monitors the position of the lift axle and offers an in-cab light and lift axle switch for axle position monitoring and lift control.
The lift and steer axle control assembly described below, its various components, manufacture, and use, provide further advancements to the available technology.